oj.uz

답안 #248393

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
248393 2020-07-12T10:50:20 Z vanic Palinilap (COI16_palinilap) C++14
100 / 100
 125 ms 26232 KB 
#include <iostream>
#include <cstdio>
#include <math.h>
#include <algorithm>
#include <vector>
#include <queue>


using namespace std;

typedef long long ll;
const int maxn=1e5+5, p=29, mod=1e9+7;

inline int sum(int a, int b){
	if(a+b>=mod){
		return a+b-mod;
	}
	else if(a+b<0){
		return a+b+mod;
	}
	return a+b;
}

inline int mul(int a, int b){
	return (ll)a*b%mod;
}


int pref[maxn], suff[maxn];
int n;
string s;
int pot[maxn];
ll sw[maxn];
ll oduz[maxn];
ll dodaj[maxn][p];
ll sol;


void precompute(){
	pot[0]=1;
	for(int i=1; i<maxn; i++){
		pot[i]=mul(pot[i-1], p);
	}
}

bool provjeri(int x, int y, int kolko){
	return sum(pref[x+1], -mul(pref[x-kolko], pot[kolko+1]))==sum(suff[n-y], -mul(suff[n-y-kolko-1], pot[kolko+1]));
}

int binary(int x, int y){
	int lo=0, hi=min(x+1, n-y), mid;
	while(lo<hi){
		mid=(lo+hi)/2;
		if(provjeri(x, y, mid)){
			lo=mid+1;
		}
		else{
			hi=mid;
		}
	}
	return lo;
}

void rijesi(int x, bool p){
	int l, d;
	if(p){
		l=x;
		d=x+1;
	}
	else{
		l=x-1;
		d=x+1;
	}
	int val;
	if(l<0 || d>=n){
		val=0;
	}
	else{
		val=binary(l, d);
	}
	l-=val;
	d+=val;
	sol+=x-l;
//	cout << x << " " << p << " " << x-l << endl;
//	cout << x << " " << p << " " << l << " " << d << '\n';
	if(p){
		sw[l+1]++;
		sw[x+1]--;
		sw[x+2]--;
		sw[d+1]++;
	}
	else{
		sw[l+1]++;
		sw[x+1]-=2;
		sw[d+1]++;
		oduz[x]+=x-l;
	}
}

void rijesi2(int x, bool p){
	int l, d;
	if(p){
		l=x;
		d=x+1;
	}
	else{
		l=x-1;
		d=x+1;
	}
	if(l<0 || d>=n){
		return;
	}
	int val;
	val=binary(l, d);
	l-=val;
	d+=val;
	if(l<0 || d>=n){
		return;
	}
	dodaj[l][s[d]-'a']++;
	dodaj[d][s[l]-'a']++;
	if(l-1<0 || d+1>=n){
		return;
	}
	val=binary(l-1, d+1);
	dodaj[l][s[d]-'a']+=val;
	dodaj[d][s[l]-'a']+=val;
}

int main(){
	ios_base::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	precompute();
	cin >> s;
	n=s.size();
	for(int i=0; i<n; i++){
		pref[i+1]=sum(mul(pref[i], p), s[i]-'a');
		suff[i+1]=sum(mul(suff[i], p), s[n-i-1]-'a');
	}
	for(int i=0; i<n; i++){
		rijesi(i, 0);
		rijesi(i, 1);
	}
	ll val=0;
	ll upd=0;
	for(int i=0; i<n; i++){
		upd+=sw[i];
		val-=upd;
		oduz[i]+=val;
	}
/*	for(int i=0; i<n; i++){
		cout << oduz[i] << " ";
	}
	cout << '\n';*/
	for(int i=0; i<n; i++){
		rijesi2(i, 0);
		rijesi2(i, 1);
	}
	ll maksi=0;
	for(int i=0; i<n; i++){
		for(int j=0; j<p; j++){
			maksi=max(maksi, oduz[i]+dodaj[i][j]);
		}
	}
	cout << sol+maksi << '\n';
	return 0;
}

Subtask #1
17.0 / 17.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 768 KB Output is correct
2 Correct 1 ms 768 KB Output is correct
3 Correct 1 ms 768 KB Output is correct
4 Correct 1 ms 768 KB Output is correct
5 Correct 1 ms 768 KB Output is correct

Subtask #2
37.0 / 37.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 2048 KB Output is correct
2 Correct 4 ms 2048 KB Output is correct
3 Correct 5 ms 2048 KB Output is correct
4 Correct 4 ms 1536 KB Output is correct
5 Correct 5 ms 1792 KB Output is correct
6 Correct 5 ms 2048 KB Output is correct
7 Correct 5 ms 2048 KB Output is correct

Subtask #3
46.0 / 46.0

# 결과 실행 시간 메모리 Grader output
1 Correct 108 ms 25976 KB Output is correct
2 Correct 91 ms 25976 KB Output is correct
3 Correct 99 ms 26104 KB Output is correct
4 Correct 108 ms 26104 KB Output is correct
5 Correct 110 ms 26148 KB Output is correct
6 Correct 107 ms 26108 KB Output is correct
7 Correct 106 ms 26104 KB Output is correct
8 Correct 64 ms 3448 KB Output is correct
9 Correct 106 ms 26104 KB Output is correct
10 Correct 109 ms 26104 KB Output is correct
11 Correct 101 ms 26144 KB Output is correct
12 Correct 125 ms 26104 KB Output is correct
13 Correct 113 ms 26232 KB Output is correct
14 Correct 111 ms 26232 KB Output is correct
15 Correct 107 ms 26104 KB Output is correct
16 Correct 123 ms 26104 KB Output is correct
17 Correct 106 ms 26104 KB Output is correct
18 Correct 110 ms 26104 KB Output is correct
19 Correct 104 ms 26104 KB Output is correct